A mower is widely used for trimming and cutting lawn to keep the lawn smooth. The existing mower generally includes an engine, a cutter head and a clutch. The engine acts as a power source for driving the cutter head through a transmission belt of the clutch, and the motion of the clutch tensions or relaxes the transmission belt, wherein the engine drives the cutter head for performing a mowing operation upon tensioning of the transmission belt, and the transmission between the engine and the cutter head is cut off upon relaxing of the transmission belt. The existing clutch is usually operated and controlled manually via a handle, which is laborious in operation and is less attractive in appearance.